It might seem odd for Mr. Trump, known for his strong US-centric rhetoric, to have a British politician speak at one of his rallies. But Mr. Farage is, in many ways, an ideological parallel to Trump from across the Atlantic. Farage was a major player in bringing about "Brexit," and his party, UKIP, is rooted in the same spirit as the anti-elitist nationalism that has propelled Trump's rise in the United States.

Despite his claims that he was not endorsing Trump, he did heavily imply his support for the Republican presidential candidate.

"I cannot possibly tell you how you should vote in this election. But you know I get it, I get it. I’m hearing you," he said to the crowd of Trump supporters. "But I will say this: if I was an American citizen I wouldn’t vote for Hillary Clinton if you paid me. In fact, I wouldn’t vote for Hillary Clinton if she paid me."

Farage played a key role in raising support for Britain's "Brexit" vote to leave the European Union on June 23. He is a founding member of UKIP, a populist political party with a strong anti-immigration policy and strong objections to the European Union. Farage led the party twice, stepping down after Britain voted to leave. According to a profile published in July by the BBC, Farage's image as a straight-talking everyman who disdained political correctness helped make UKIP the third-largest political party in Britain.

Trump has cultivated a similar image in US politics. Like Farage, he has repeatedly denounced political correctness. According to a 2015 poll by MSNBC, 71 percent of Republican voters thought Trump "tells it like it is," a persona the Republican candidate shares with Farage. According to the BBC, Farage has used this perception to attack political rivals that he was able to paint as too entrenched in the political establishment, a similar strategy that Trump used to defeat his opponents during the primaries.

"Anything is possible if enough decent people are prepared to stand up against the establishment," Farage told the Trump supporters at the Wednesday rally, evoking similar rhetoric that he used during the Brexit campaign.

At the rally in Jackson, Trump expressed admiration for the so-called Brexiteers. "I was very supportive of their [Britain's] right to do it and to take control of their own future, like we're going to be voting for on November 8th," Trump told rally attendees, according to media reports. "They voted to reclaim control over immigration, over their economy, over their government."

The Farage speech comes as Trump's poll numbers sag. The candidate's fiery, anti-establishment image that propelled him to the Republican nomination has not earned him much support from moderate voters.

During Farage's speech, however, Farage told Trump supporters that they could "beat the pollsters," pointing out that most British polls before Brexit indicated that the country would vote to stay in the EU.

"No citizenship. Let me go a step further – they'll pay back taxes, they have to pay taxes, there's no amnesty, as such, there's no amnesty, but we work with them," Trump said in an interview with Fox News. "But when I go through and I meet thousands and thousands of people on this subject, and I've had very strong people come up to me ... and they've said: 'Mr. Trump, I love you, but to take a person who's been here for 15 or 20 years and throw them and their family out, it's so tough, Mr. Trump.' "